[mutter/wip/carlosg/hidpi-input-opaque-regions: 9/10] wayland: Fix input/opaque regions calculation on hidpi

[Jonas Ådahl <jadahl src gnome org>]

commit 784a774d9cfcba39a1dc33e7af32ff7f8efed31b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Aug 22 16:22:58 2018 +0200

    wayland: Fix input/opaque regions calculation on hidpi
    
    Commit 6a92c6f83 unintendedly broke input/opaque region calculations
    on hidpi. Most visible side effect is that clicking is only allowed
    in the upper-left quarter of windows.
    
    The surface coordinates are returned in logical unscaled buffer
    size. We're however interested in actor coordinates (thus real
    pixels) here.
    
    As it is a bit of a detour how the scale to be applied is calculated,
    refactor a meta_wayland_actor_surface_get_geometry_scale() function
    that we can use it here, and use it consistently for surface size and
    the given regions.

 src/wayland/meta-wayland-actor-surface.c | 40 +++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 14 deletions(-)
---
diff --git a/src/wayland/meta-wayland-actor-surface.c b/src/wayland/meta-wayland-actor-surface.c
index 3c60ed56e..c05be63eb 100644
--- a/src/wayland/meta-wayland-actor-surface.c
+++ b/src/wayland/meta-wayland-actor-surface.c
@@ -99,32 +99,43 @@ queue_surface_actor_frame_callbacks (MetaSurfaceActorWayland *surface_actor,
   wl_list_init (&pending->frame_callback_list);
 }
 
-double
-meta_wayland_actor_surface_calculate_scale (MetaWaylandActorSurface *actor_surface)
+static double
+meta_wayland_actor_surface_get_geometry_scale (MetaWaylandActorSurface *actor_surface)
 {
   MetaWaylandSurfaceRole *surface_role =
     META_WAYLAND_SURFACE_ROLE (actor_surface);
   MetaWaylandSurface *surface =
     meta_wayland_surface_role_get_surface (surface_role);
   MetaWindow *toplevel_window;
-  int geometry_scale;
 
   toplevel_window = meta_wayland_surface_get_toplevel_window (surface);
   if (meta_is_stage_views_scaled ())
     {
-      geometry_scale = 1;
+      return 1;
     }
   else
     {
       if (!toplevel_window ||
           toplevel_window->client_type == META_WINDOW_CLIENT_TYPE_X11)
-        geometry_scale = 1;
+        return 1;
       else
-        geometry_scale =
-          meta_window_wayland_get_geometry_scale (toplevel_window);
+        return meta_window_wayland_get_geometry_scale (toplevel_window);
     }
+}
+
+double
+meta_wayland_actor_surface_calculate_scale (MetaWaylandActorSurface *actor_surface)
+{
+  MetaWaylandSurfaceRole *surface_role =
+    META_WAYLAND_SURFACE_ROLE (actor_surface);
+  MetaWaylandSurface *surface =
+    meta_wayland_surface_role_get_surface (surface_role);
+  double geometry_scale;
 
-  return (double) geometry_scale / (double) surface->scale;
+  geometry_scale =
+    meta_wayland_actor_surface_get_geometry_scale (actor_surface);
+
+  return geometry_scale / (double) surface->scale;
 }
 
 static void
@@ -141,6 +152,7 @@ meta_wayland_actor_surface_real_sync_actor_state (MetaWaylandActorSurface *actor
   double actor_scale;
   GList *l;
   cairo_rectangle_int_t surface_rect;
+  int geometry_scale;
 
   surface_actor = priv->actor;
   stex = meta_surface_actor_get_texture (surface_actor);
@@ -148,20 +160,20 @@ meta_wayland_actor_surface_real_sync_actor_state (MetaWaylandActorSurface *actor
   actor_scale = meta_wayland_actor_surface_calculate_scale (actor_surface);
   clutter_actor_set_scale (CLUTTER_ACTOR (stex), actor_scale, actor_scale);
 
+  /* Wayland surface coordinate space -> stage coordinate space */
+  geometry_scale = meta_wayland_actor_surface_get_geometry_scale (actor_surface);
+
   surface_rect = (cairo_rectangle_int_t) {
-    .width = meta_wayland_surface_get_width (surface),
-    .height = meta_wayland_surface_get_height (surface),
+    .width = meta_wayland_surface_get_width (surface) * geometry_scale,
+    .height = meta_wayland_surface_get_height (surface) * geometry_scale,
   };
 
   if (surface->input_region)
     {
       cairo_region_t *scaled_input_region;
-      int region_scale;
 
-      /* Wayland surface coordinate space -> stage coordinate space */
-      region_scale = (int) (surface->scale * actor_scale);
       scaled_input_region = meta_region_scale (surface->input_region,
-                                               region_scale);
+                                               geometry_scale);
       cairo_region_intersect_rectangle (scaled_input_region, &surface_rect);
       meta_surface_actor_set_input_region (surface_actor, scaled_input_region);
       cairo_region_destroy (scaled_input_region);